Merge group hierarchies when parents are shared

2 files changed, 40 insertions, 0 deletions

diff --git a/app/serializers/base_serializer.rb b/app/serializers/base_serializer.rb
index 4e6c15f673b..d78108480d3 100644
--- a/app/serializers/base_serializer.rb
+++ b/app/serializers/base_serializer.rb
@@ -1,5 +1,8 @@
 class BaseSerializer
+  attr_reader :parameters
+
   def initialize(parameters = {})
+    @parameters = parameters
     @request = EntityRequest.new(parameters)
   end
 
diff --git a/app/serializers/group_child_serializer.rb b/app/serializers/group_child_serializer.rb
index fbf4a6783b9..ed84c3ae1d7 100644
--- a/app/serializers/group_child_serializer.rb
+++ b/app/serializers/group_child_serializer.rb
@@ -1,5 +1,42 @@
 class GroupChildSerializer < BaseSerializer
   include WithPagination
 
+  attr_reader :hierarchy_root
+
   entity GroupChildEntity
+
+  def expand_hierarchy(hierarchy_root)
+    @hierarchy_root = hierarchy_root
+    self
+  end
+
+  def represent(resource, opts = {}, entity_class = nil)
+    if hierarchy_root.present?
+      represent_hierarchies(resource, opts)
+    else
+      super(resource, opts)
+    end
+  end
+
+  def represent_hierarchies(children, opts)
+    if children.is_a?(GroupHierarchy)
+      represent_hierarchy(children.hierarchy(hierarchy_root), opts)
+    else
+      children.map { |child| represent_hierarchy(child.hierarchy(hierarchy_root), opts) }
+    end
+  end
+
+  def represent_hierarchy(hierarchy, opts)
+    serializer = self.class.new(parameters)
+
+    result = if hierarchy.is_a?(Hash)
+               parent = hierarchy.keys.first
+               serializer.represent(parent, opts)
+                 .merge(children: [serializer.represent_hierarchy(hierarchy[parent], opts)])
+             else
+               serializer.represent(hierarchy, opts)
+             end
+
+    result
+  end
 end